The Chestnut Street bridge over the Schuylkill is closing next week, and it won’t be open to traffic again for a year.

The 62-year-old span needs repairs, PennDot reported Tuesday, including repairing and repainting the steel superstructure and replacing the deck. The structure also will be upgraded with a bike lane, wider sidewalks, and decorative railings.

The closure, beginning about 8 p.m. Monday, will bar Chestnut Street traffic from Schuylkill Avenue to 23rd Street. Pedestrians will not be able to access the Schuylkill River Trail from Chestnut during the repair project.

About 18,700 cars a day cross the bridge, built in 1957.

The work is part of a $103.6 million project that also will affect two Schuylkill Avenue crossings over I-76, the I-76 west ramp to Chestnut Street, the Walnut Street ramp to I-76 east, and the stone arch bridges on Chestnut Street over 24th Street and railroad tracks. Portions of walls along the river also will be repaired. The prime contractor on the project is Buckley & Co. of Philadelphia.

Eastbound traffic will be routed onto 38th Street, 36th Street, or 33rd Street to Market Street, then to 23rd Street. Drivers also can turn onto Schuylkill Avenue from 30th Street. Cyclists can follow the same detours as cars, or can travel on 38th Street or 34th Street south, go left onto Spruce Street, then cross the river at South Street. People on foot will be routed to Market or Walnut Streets.

Motorists can check conditions on more than 40,000 roadway miles by visiting www.511PA.com or downloading the 511PA app for iPhone and Android devices. The 511PA app, which is free and available 24 hours a day, provides traffic delay warnings, weather forecasts, traffic speed information, and access to more than 950 traffic cameras.